Refractory Ascitis Diagnosis by the Study of Labelled Albumin Pharmacokinetics (ARAM)

Main objective: assess the performances of PK parameters (transfer of labelled albumin) between peritoneal and vascular compartments, for the diagnosis of refractory ascitis, in patients with cirrhosis and abundant ascitis.

Design: proof of concept study. Interventional cross-sectional study in Beaujon Hospital (Clichy, France), 1 recruiting center and 1 non recruiting center.

Patients are recruited in the Hepatology department (Pr Valla) and PK exploration is performed in the nuclear medicine department (Pr Lebtahi) of Beaujon Hospital.

Description of intervention: diuretics treatment discontinuation 7 days before exploration for patients with sensitive ascitis, and more than 7 days for those with refractory ascitis. The day of exploration, the patients come to hospital and stay in lying position. One intra-veinous injection of 0,015 megabecquerel(MBq) /Kg labelled human serum albumin (Iode-125 (125-I), Séralb®CisBio), in compliance with market authorization, simultaneously to one intra-peritoneal injection of 200 MBq of labelled albumin (Technetium 99m (99m-Tc), Vasculocis®, Cisbio), off-label used. It follows 5 minutes mobilization of the patient (right and left lateral decubitus), then a scintigraphy will be performed using a gamma-camera Symbia T2 (Siemens®). Repeated blood (5 ml) and peritoneal ascitis (3 ml) samples are performed before injection and every 30 minutes for 6 hours (catheter in place). Diuretic treatment can be restarted the day after PK explorations. Patients are followed-up at 1 month by phone call (for the collection of adverse events).

Measurements : radioactivity measurements of 99m-Tc and 125-I in the biological samples are performed by a counter device in the nuclear medicine department (Wizard 3000, Packard®). Unidirectional transfer of labelled albumin (125-I) from vascular compartment (plasma-P) to peritoneal compartment (ascitis-A) (TPA), Unidirectional transfer of labelled albumin (99m-Tc) from peritoneal (A) to vascular compartment (P) (TAP), and the ratio TPA/TAP are calculated from these measurements using Matlab®.The gold standard is defined by the diagnosis of refractory ascitis performed before inclusion.

Statistical analyses: performances of the TAP, of the TPA, and of the ratio TPA/TAP for the diagnosis of refractory ascitis, will be computed using the Receiver Operating Characteristic (ROC) curve.

Number of patients : 30 patients (15 patients with refractory ascitis and 15 patients with sensitive or untreatable ascitis) will be included during a 24 months period (1 or 2 patients per month), and followed-up for 2 months. The PK explorations will be performed in nuclear medicine department not more than 4 weeks after inclusion. Total length of study will be of 26 months.